From 2c59f669553677838022d65f2433b31a04bc632d Mon Sep 17 00:00:00 2001 From: Laurent Bercot Date: Tue, 5 May 2015 13:10:13 +0000 Subject: - add trap - rc for 2.1.2.0 --- doc/index.html | 5 +-- doc/trap.html | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ doc/upgrade.html | 7 ++++ 3 files changed, 108 insertions(+), 2 deletions(-) create mode 100644 doc/trap.html (limited to 'doc') diff --git a/doc/index.html b/doc/index.html index dda1445..5fb4b3c 100644 --- a/doc/index.html +++ b/doc/index.html @@ -51,7 +51,7 @@ shell's syntax, and has no security issues.

GNU make, version 4.0 or later. Please be aware that execline will not build with an earlier version.

skalibs version -2.3.3.0 or later. It's a build-time requirement. It's also a run-time +2.3.4.0 or later. It's a build-time requirement. It's also a run-time requirement if you link against the shared version of the skalibs library.

@@ -66,7 +66,7 @@ library.

Download

The current released version of execline is 2.1.1.1.
The current released version of execline is 2.1.2.0.
Alternatively, you can checkout a copy of the execline git repository:
```
 git clone git://git.skarnet.org/execline 
```

@@ -136,6 +136,7 @@ to your installation: the shebang lines for your system might be something like

The exec program

The tryexec program

The exit program

The trap program

(Basic block management) diff --git a/doc/trap.html b/doc/trap.html new file mode 100644 index 0000000..ff03c2e --- /dev/null +++ b/doc/trap.html @@ -0,0 +1,98 @@ + + + + + execline: the trap command + + + + + + +

+execline
+Software
+skarnet.org +

+ +

The `trap` program

+ +trap traps signals and runs a variety of commands according +to the signals it catches. + +

Interface

+ +

+ In an execlineb script: +

+ +

+     trap [ -x ] [ -t millisecs ]
+     {
+       [ timeout { progtimeout... } ]
+       [ SIGTERM { progsigterm... } ]
+       [ quit { progsigquit... } ]
+       [ 1 { progsighup... } ]
+       ...
+     }
+     prog...
+

+ +

trap reads a sequence of directives in a +block. It expects at least one +directive.
Each directive is a keyword followed by a block.
The keyword can be the special word timeout, a signal +name (case-insensitive, with or without the SIG prefix), + or a signal number. The block following it is a command line to +run when the specified event occurs.
trap sets traps for the various directives it reads. +A trap for SIGTERM will be triggered when the trap +program receives a SIGTERM. +A trap for timeout will be triggered when millisecs +milliseconds elapse without a signal being caught.
It spawns a child executing prog....
It sets the ! environment +variable to the pid of the prog... process.
Whenever it catches a signal, it spawns the program described in the +corresponding directive. It will not spawn a program for the same signal +twice: if the first subprocess is still active when another instance of the +same signal arrives, this second instance is ignored.
When prog... exits, trap exits with an +approximation of the same exit code.

+ +

Options

+ +

-x : forward signals. If this option is given, +any signal that trap receives and that is not explicitly +trapped will be sent to prog. By default, trap does +not forward any signals, and does not ignore them either - for instance a +SIGTERM, unless caught by a SIGTERM directive, will kill the +trap process (and leave prog running). With the +-x option, without a SIGTERM directive, a SIGTERM +will be still be caught by trap, that will send it to +prog.
-t millisecs : if a timeout +directive exists, the corresponding progtimeout... will be run +every time millisecs milliseconds elapse without trap +receiving a signal. By default, millisecs is 0, which means +infinite (i.e. a timeout directive will never trigger).

+ +

Notes

+ +

Programs defined in command line directives can start with +import ! to retrieve the pid of +prog in ${!}
trap is a standard shell builtin, with similar +functionality. It is more idiomatic, and probably more efficient, +to use that builtin in shell scripts, and to only use the +trap program in execline scripts.

+ + + diff --git a/doc/upgrade.html b/doc/upgrade.html index 121b210..ff1d40d 100644 --- a/doc/upgrade.html +++ b/doc/upgrade.html @@ -17,6 +17,13 @@

What has changed in execline

in 2.1.2.0

+ +

skalibs dependency bumped to 2.3.4.0
new command: trap

in 2.1.1.1

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